The present invention relates to NC machining simulation apparatuses and methods in which machining is simulated in accordance with an NC machining program.
Conventionally, an NC machining simulation apparatus having a display device is known. The display device displays a tool and a workpiece in accordance with an NC machining program. The apparatus changes the position of the tool and the shape of the workpiece that are displayed on the display device, when necessary. The movement of the tool and the machining state of the workpiece are thus identified through the display device. Using the simulation apparatus, machining is simulated in accordance with the NC machining program before actual operation so as to ensure that a tool movement path defined by the NC machining program is optimal for the machining.
For example, Japanese Laid-Open Patent Publication No. 2002-82704 describes an NC machining simulation apparatus that analyzes an NC machining program successively in accordance with execution blocks. The apparatus includes an image data generation processing section that generates image data successively for each of the execution blocks using pixel data regarding the shape of a tool and the shape of a workpiece in correspondence with tool shape data and workpiece shape data. The tool shape data is stored in a tool data memory and the workpiece shape data is stored in a workpiece shape data memory. The apparatus also includes a block image data memory for storing the image data generated by the image data generation processing section for each execution block. The tool and the shape of the workpiece are displayed on a display device in correspondence with the image data. The positions of the tool and the workpiece relative to each other and the machining state of the workpiece are thus identified by means of the apparatus.
However, the aforementioned document does not address the position of a mechanical element other than the tool including peripheral components such as a workpiece main shaft a main shaft chuck, and a cutter table relative to the position of the tool. Further, other peripheral components including a tool main shaft located in the periphery of the tool and a holder for securing the tool to the tool main shaft may interfere with a different mechanical element.
Therefore, for identifying relative positions, or interference states, of mechanical elements, the NC machining simulation apparatus of the above document may generate image data regarding the tool and the mechanical elements other than the tool for each of the execution blocks. However, since the image data is stored in the block image data memory, the capacity of the memory must be increased correspondingly. Such modification is impractical.